Process of enriching gas.



"No. 728,991. PATENTED MAY 26, 1903.

F. W. G-.'SGHNIEWIN D.

PROCESS OF ENRIGHING GAS.

APPLICATION FILED JAN. 23. 1900. N0 MODEL.

UNITED STATES Patented May 26, 1903.

PATENT OFFICE.

FREDERIO WILLIAM CHARLES SCHNIEWIND, OF EVERETT, MASSACHUSETTS, ASSIGNOR TO THE UNITED COKE & GAS COMPANY, OF CHARLESTON, WEST VIRGINIA, AND PHILADELPHIA, PENNSYLVANIA, A CORPORATION OF WEST VIRGINIA.

PROCESS OF ENRICHING GAS.

SPECIFICATION forming part of Letters Patent No. 728,991, dated May 26, 1903.

Application filed January 23, 1900.

To all whom it may concern:

Be it known that I, FREDERIC WILLIAM CHARLES SOHNIEWIND, a citizen of the United States of America, residing in Everett, in the county of Middlesex and State of Massachusetts, have invented a certain new and Improved Process of Utilizing Benzol from Tars in the Manufacture of Gas, of which the following is a true and exact description, reference being had to the accompanying drawing,

which forms a part thereof.

My invention relates to the manufacture of gas, and has for its object, primarily, to increase the illuminating value and richness of the gas by saving and mixing with it free from deleterious admixture the benzol and its homologues which are in solution in the coaltar.

A further object which I have in view in the preferred practice of my method is the addition of the benzol from the tar in such a way as to prevent the condensation and deposition in the condensing and purifying apparatus of solid hydrocarbons, this being accomplished by adding the benzol from the tar to the gases to be enriched either before or during their passage through the condensinghouse.

The nature of my method will be best un- 3o derstood as described in connection with the drawing, which is a diagrammatic representation of a coking and gas making plant equipped for the convenient utilization of my present invention, A indicating a bank of 5 closed externally-heated coke-ovens, the separate ovens being indicated at A A A &c., and each oven having, as shown, two outletconduits, one (indicated at a) for the richer fraction of gas given off during the earlier 0 stages of the coking of bituminous coal and the other (indicated at a) being for the outlet for the poorer fraction of the gases given off during the latter stages of the coking. These outlet-conduits a and a are connected by 4 5 pipes 0. each having in them a valve a either with the rich-gas main (indicated at O) or the poor-gas main, (indicated at O.)

B indicates the condensing-house of the and N plant, which is divided into two systems, one

Serial No. 2,436. (No specimens.)

(indicated at B forthe rich gases andthe other (at B) for the poorer gases, B B and b indicating coolers and scrubbers, E, E, and e washers, and B pressure-blowers situated between the condensers and washers.

0 indicates the rich-gas main, leading from the condenser house, and 0 the poor-gas main, also leading from the condenser-house.

D indicates what I may callthe benzol house, containing apparatus for utilization in the process of extracting illuminants from the gas, 0 indicating a conduit leading from the benzol-washer, through which the poorer fraction of the gas, robbed of its illuminants, is conducted back to the coking-ovens to be utilized in heating them, and 0 indicating a pipe through which the benzol extracted from the gases is led away for use, storage, or further treatment.

The process indicatedby which the gases from the ovens are fractionized into richer 70 and poorer volumes and in which the poorer gas before utilization is robbed of its illuminants forms the subject-matter of my two applications for Letters Patent, one filed January 8, 1900, Serial No. 653, and the other filed January 22, 1900, Serial No. 2,313, and need not be further described in this specification.

M, M, and M indicate tar-wells, the main well M being, as shown, connected directly with the main 0 and O by the tar-pipes N and N and being also connected with the tarwells M and M by means of the tar-pipes N The tar-well M is connected by the tar-pipes N and N to receive the drainage from the cooling and condensing devices, (indicated at B B and 19 and tar-Well M is connected by the tar-pi pes N and N to receive the tar condensed and collected in the washers E, E,and e. The tar-well M is further connected by a pipe N having in it a valve a with the tar-still, (indicated at 0,) having a valve-outlet (indicated at 0) for pitch. From the top of still 0 leads the pipe P, of which one division P, with valve 13, connects with a coil Q ina condensing-tank Q and through said coil with a distributing-pipe Q The other branch P of the pipe P connects, as shown,

- its homologues, is subjected to a fractional said reservoirs being connected by pipes R R 850., with the distributing-pipe Q each of the connecting-pipes having in it a valve, as indicated at r 0" T 850.

In the practice of my invention the tar contained inthe reservoir M or in any convenient reservoir,which generally contains a commercially-valuable percentage of benzol and distillation in the still indicated at O or in any suitable tar-still, and during the earlier stages of the distillation the pipe P is closed, as by closing the valves 19 and p and the reservoir S placed in connection through the pipe P and Q by opening the valve 0", the other reservoirs S S 850., being closed. The bisulfid of carbon, which is the first distillate driven off from the coal-tar, is then condensed in the condenser Q and collected in the reservoir S. After the bisulfid of carbon, which is highly injurious as an ingredient of gas, is separated from the tar and collected in the reservoir S the valve 1" is closed and either the valve p or p opened, so that the tar distillates next given olf, which consist of benzol and its homologues, will be delivered into the rich-gas main 0, imparting additional illuminating value and, indeed, increasing the value of the gas for other uses besides as an illuminant. and its homologues are driven from the tar and mixed with the gas the valves p p are closed and the distillates of higher boiling-point collected in'the reservoir S S S 850., by opening one at a time of the valves 4" 1*, 850., in accordance with the distillate passing off from the still at any given time and known temperature.

My reason for preferring to mix the benzoldistillate fraction from the tar with the gases to be enriched before or during their passage through the condensing system is twofold. Primarily the increased percentage of benzol added to thegas has a marked tendency to bring the solid hydrocarbons which tend to deposit in the apparatus into solution, so that they will flow out in admixture with the fluids passing from the condensing-house to the tar-wells. This of course involves some diminutionin the percentageiof benzol which leaves the condenser-house with the gases; but the loss is not considerable and is all practically recovered in the subsequent fractional distillation of the tars. Another rea- After the benzol,

son for preferring to add the benzol prior to the completion of the condensing operation on the gases is that by doing so I eliminate from the gas any undesirable constituents which may pass from the tan in admixture with the benzol.

The distillation of the tars is facilitated by forcing through the still a volume of' gas, which rapidly carries away the distillate, and this in the plan illustrated can be efiected without loss of gas by connecting a perforated bent pipe, as T situated in the still, with conduits leading from the poor and rich gas mains (each provided with valves) and by connecting the pipe Q with the poor-gas main. Thus T is a pipe leading from the rich-gas main and having a valve 25. T is a pipe leading from the poor-gas main having a valve t, the pines T and T connecting ,through a pipe T with the perforated pipe T, U indicating a blower in pipe T T is a pipe connecting pipe Q with the poor-gas main 0. When the bisulfid of carbon is being separated, the valve if is closed and valve t opened. The poor gas from main 0 is then forced through the still and passes from it mixed with the bisulfid into the condenser Q, where the bisulfid is condensed and after- Ward collected in reservoir S, while the gas passes through conduit Q and pipe T back to the poor-gas main 0. During the subsequent separation of the benzol in the tar the valve t is closed and the valve t opened, so that rich gas is passed through the still and passes with the benzol, valve 19 being closed, back into the rich-gas main 0. After the benzol is separated the valves 25 and t are again shifted and the remaining separations carried on with the poor gas passing through the still, the distillates condensing in condenser Q, and the gas again being passed back to the poor-gas main, as before.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is-

In the manufacture of gas in closed externally-heated retorts, the method of improving its quality which consists in separating the richer and poorer gases generated, subjecting a body of tar containing benzol and its homologues to fractional distillation to volatilize and separate from other volatile matters the valuable illuminants and during the stage of the distillation in which the benzol is volatilized forcing through the still some of the richer fraction of gas generated in the retorts, and finally mixing the said gas and benzol removed from the still with the said richer fraction of gas.

FREDERIO WILLIAM CHARLES SCHNIEWIND. 

